|By Tatiana Jancarikova and Jason Hovet

BRATISLAVA (Reuters) - Ukraine is doing less than Russia to meet its obligations under the Minsk peace plan, Slovakia's Prime Minister Robert Fico said on Saturday, stepping up calls for the European Union to end sanctions against Moscow.

Fico said sanctions have been ineffective while harming European Union and member Slovakia's economic interests. But added he would respect EU solidarity on the issue.

"When speaking about the implementation of the Minsk agreement, it needs to be said clearly that both parties are violating it. Actually, if we were to do an inventory of how Ukraine is meeting it, you would have to say Ukraine is meeting it even less than Russia," Fico told Reuters in an interview.

"With the Minsk agreement (to bring peace in Ukraine), it is necessary to take stock. It is not true that Ukraine is the good guy and Russia is the bad guy," he said.

The EU imposed energy, financial and defense sanctions on Moscow after it annexed Ukraine's Crimea in 2014 and agreed in June to extend them until the end of January.

Fico has repeatedly called for the end of the sanctions, most recently after meeting President Vladimir Putin in Moscow in August.

German Chancellor Angela Merkel urged Ukrainian President Petro Poroshenko in a phone call on Saturday to do his part in implementing the peace plan.

"The Chancellor expressed the opinion that the coming weeks must be used to take a decisive step forward," a German government spokeswoman said, adding Merkel told Poroshenko it was essential that both Russia and Ukraine demonstrated the political will to reach an agreement.

Merkel said last month there was no reason to lift sanctions as Russia has not fulfilled its commitments under the Minsk agreements aimed at ending the conflict in eastern Ukraine where Kiev and the West say Russia is arming and supporting separatist rebels.

Germany's Social Democrats, junior partner in Merkel's ruling coalition, have adopted a more conciliatory stance toward Moscow than her conservative bloc.

Foreign Minister Frank-Walter Steinmeier, a senior SPD member, has said the EU should gradually phase out sanctions imposed against Russia over the Ukraine crisis if there is substantial progress in the peace process.

But Merkel insists the sanctions can only be lifted once the peace agreement is fully implemented, not partially.

Fico said on Saturday the sanctions had done nothing to change Russian policy. "Sanctions are harming the EU and Russia and they help the United States. I reject them but at the same time I won't break the unity of the EU on that," he said.

Slovakia holds the rotating EU presidency until the end of this year.

The central European country imports almost all its gas and oil from Russia, as well as nuclear fuel to generate two power plants. It exports cars to Russia, though these are just a fraction of its exports to the EU.

Some neighboring countries have also questioned the use of sanctions on Russia. Hungary has taken a similar line as Slovakia. Czech President Milos Zeman has also repeatedly called for ending sanctions.